Bulk properties of single crystals of the valence-unstable compound SmRh2Si2

Abstract

We present the crystal growth as well as the structural, chemical and physical chracterization of SmRh2Si2 single crystals. Their ground state is antiferromagnetic, as indicated by the behaviour of the magnetic susceptibility and the specific heat at the second order phase transition observed at T N = 64 K. The Sommerfeld coefficient is small and similar to that of LuRh2Si2 with mJ/(molK2). Susceptibility measurements show no Curie-Weiss behaviour at high temperatures which is a consequence of the large Van-Vleck contribution of the excited multiplets of Sm3+. Previous angle-resolved photoemission studies showed that at 10 K, the valence of the Sm ions is smaller than three at the surface as well as in the bulk, suggesting a possible Kondo screening of the Sm3+ ions. This could not be observed in our thermodynamic and transport measurements.